A hub of online professional and topical glossaries/dictionaries
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A.I.D.  look up translate image
Automatic Incident Detection.
A.M. PEAK HOUR  look up translate image
The one hour in the morning when traffic volumes are highest.
A.M. PEAK PERIOD  look up translate image
The period (rush hour) in the morning when traffic volumes are highest
AADT  look up translate image
Average Annual Daily Traffic.
AASHTO  look up translate image
American Association of State Highway and Transportation Officials.
ABRASION (PAVEMENT MARKINGS)  look up translate image
A condition manifested in pavement markings by gradual surface erosion, thinning, and disappearance of the film due to wind, water, sand, and vehicle tire wear.
ACCELERATION  look up translate image
A rate of change of speed (km/h/sec or m/seC2) resulting in an increase in travel speed.
ACCELERATION LANE  look up translate image
A speed change lane for the purpose of: (1) enabling a vehicle entering a roadway to increase its speed to a rate at which it can more safely merge with through traffic: (2) providing the necessary merging distance: and (3) giving the main road traffic the necessary time to make appropriate adjustments.
ACCESS  look up translate image
A way of entering or travelling towards a location. It is used when describing which vehicle movements may be permitted at an intersection (such as with an access-only barrier). It is also used when describing the location of driveways and walkways which provide an entrance to a property. See Egress and Ingress.
ACCIDENT  look up translate image
See Collision.
ACTUATED OPERATION  look up translate image
Type of traffic signal control operation in which some or all signal phases are actuated from vehicle detectors.
ACTUATION  look up translate image
The operation of a detector in registering the presence or passage of a vehicle or pedestrian.
ADVANCE WARNING AREA  look up translate image
The first component of a work zone, upstream of the approach area, used to alert drivers to road work ahead.
The application of advanced electronic and communications technologies to improve the safety and efficiency of public transit systems. See also Intelligent Transportation Systems (ITS).
Systems using high-technology devices, on both freeways and urban streets, to more efficiently manage traffic. These include roadside sensors, ramp metering, cameras, dynamic message signs, HOV lanes and synchronized traffic signals that respond to traffic flows.
This system provides travellers with information to help in trip planning and changing course en route to bypass congestion, e.,g., broadcast traffic reports, in - car computerized maps and highway DMSS. Also can include automated transit trip planning and automated rideshare matching.
ADVISORY MAXIMUM SPEED  look up translate image
An advisory speed posted when the roadway geometries result in a maximum safe speed which is 20 km/h or more below the operating speed, and is 10 km/h or more below the regulatory speed limit.
ADVISORY SPEED  look up translate image
The speed, determined to the nearest 5 km/h, at which traffic may safely negotiate a potential hazard under favourable driving conditions.
AIR BRAKE  look up translate image
A brake in which the mechanism is actuated by the manipulation of air pressure. The term is often used to describe brakes that employ air under pressure above atmospheric, in contrast to vacuum brakes, which employ pressure below atmospheric.
ALL-RED INTERVAL (TRAFFIC SIGNAL)  look up translate image
The time in seconds of a red indication for all intersection traffic. It is used following an Amber Clearance Interval to permit vehicles or pedestrians to clear the intersection before conflicting traffic receives a green indication. In Temporary Conditions, the All-red Interval is used to clear a one-lane section through a work site before opposing traffic receives a green indication.
The clearance interval in which the signal indication for that Phase is amber. A clearance interval to warn approaching traffic to clear the intersection before conflicting traffic receives a green indication.
ANNUAL AVERAGE DAILY TRAFFIC (AADT)  look up translate image
The total yearly traffic volume on a given road divided by the number of days in the year.
The total yearly traffic volume on a given road collected on weekdays and divided by the number of weekdays (252 or 253 days) in the year. Traffic volumes on statutory holidays are not included.
APPROACH AREA  look up translate image
The second component of a work zone, downstream of the advance warning area, and upstream of the transition area, in which the driver is informed of lane changes, speed reductions, passing restrictions and the like.
APPROACH NOSE  look up translate image
The end of a traffic island first encountered by a road user approaching from a given direction- also called the Upstream End. Depending on the situation, traffic may pass only to the right of the island, or on both sides. Each traffic island has two approach ends, one for each direction of travel.
APPROACH SPEED  look up translate image
The maximum safe speed that can be maintained over a short section of highway immediately in advance of a potentially hazardous location, taking into account pavement and shoulder width, horizontal and vertical alignment, sight distance, and other controlling factors. The approach speed does not necessarily coincide with the Design Speed.
APTS  look up translate image
Advanced Public Transit Systems. See Intelligent Transportation Systems (ITS).
AREA PARKING CONTROL  look up translate image
A parking control plan for an area or community.
ARTERIAL ROAD  look up translate image
A Major Road, used primarily for through traffic rather than for access to adjacent land, that is characterized by high vehicular capacity and continuity of movement. Intersections are spaced relatively far apart and are frequently signalized. See also Collector Road and Local Road.
ASSURANCE SIGN  look up translate image
A Directional Guide Sign or Trailblazer, providing confirmation to the travellers that they are on the desired route or road, and/or are traveling toward the desired destination.
ASTM  look up translate image
American Society for Testing and Materials.
AT-GRADE INTERSECTION  look up translate image
An intersection of two roadways where there is no vertical separation between the two roadways at their point of intersection.
ATC  look up translate image
Area Traffic Control.
ATIS  look up translate image
Advanced Traveller information Systems.
ATMS  look up translate image
Advanced Traffic Management Systems.
ATSSA  look up translate image
American Traffic Safety Services Association.
Vehicles equipped with AVI transponders are identified when they come within range of a roadside communication unit. Most common application is for automatically collected tolls on toll highway: however, the system may also be used as a means of automatically collecting travel time information along freeways.
A commercial vehicle electronic clearance system along Highway 401 (Windsor to Whitby) and Interstate 1-75 in the U.S.
AUTOMATIC VEHICLE LOCATION (AVL)  look up translate image
A system which enables the approximate location of a vehicle to be determined and tracked as it traverses the transportation network. Commonly used by emergency services and transit agencies to track location of vehicles. Also can be used to monitor traffic conditions by obtaining probe reports from vehicles travelling in the network.
AVC  look up translate image
Automated Vehicle Classification.
AVERAGE DAILY TRAFFIC (ADT)  look up translate image
The total volume during a given time period in whole days greater than one day and less than one year divided by the number of days in that time period.
AVG  look up translate image
Automated Vehicle Guidance.
AVI  look up translate image
Automatic Vehicle Identification.
AVION  look up translate image
Automatic Vehicle Identification in Ontario.
AVL  look up translate image
Automatic Vehicle Location.
BAILEY BRIDGE  look up translate image
See Temporary Bridge.
BALL BANK INDICATOR  look up translate image
A mechanical or electronic device that can be mounted inside a four-wheel vehicle. Readings of the ball bank indicator show the combined effects of the body rolling angle, centrifugal force and superelevation angle to estimate the safe operating speed around a curve.
BARRICADE  look up translate image
A device which provides a visual indicator of a hazardous location or the desired path a motorist should take, but is not intended to contain or redirect a vehicle. A barricade is intended to provide separation or to inform of closure, or to provide direction to pedestrians. A barricade is not a primary means of providing direction to motorists, but is supplemental to other traffic control devices providing delineation.
BARRIER  look up translate image
A device which provides a physical limitation, through which a vehicle would not normally pass, and is intended to contain or redirect an errant vehicle of a particular size range, at a given speed and angle of impact.
BASE PERIOD  look up translate image
See Off-peak Period.
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Traffic control terms
Visibility Public
Created by admin
Created on 2012-08-15 08:03:52
Number of terms 635
Last added None
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